The present invention pertains to a new type of skid device designed to equip powered support chock blocks of the same type as those that are used in mines. In particular, the support of the present invention is used for coal shortwall mining.
Usually, an armored coal conveyor is placed along the working face of the mine. The support chock blocks are respectivly perpendicular with the direction of the armored conveyor behind which they are aligned next to one another. The pads of each chock block or chock block assembly are connected with the armored conveyor by one or several horizontal skid cylinders. Traditionally, upon completion of mining at a given station, the skid operations are performed as follows.
During the first stage and with the chock blocks pressed against the top, each skid cylinder pushes the respective end of the armored conveyor forward. After the conveyor comes to a stop in its new position, each chock block is released and moved forward under the action of the skid cylinder which is actuated in a direction opposite to that of the first stage.
As soon as each chock block has been skidded to its new position, it is pressed against the top and the site is ready to be used as a new mining station.
Generally, during all of these operations, the back of the chock block, which constitutes a driving shield, remains exposed to possible rock falls from old workings.
During operation, traditional skid devices offer two types of disadvantages. First, the skid device defines an excessive length at the back of the chock block, particularly when the latter is very close to the armored conveyor and this disadvantage is particularly noticeable in the case of short chock blocks. Second, the back of the skid device, and particularly its relatively fragile hydraulic components, is exposed, behind the chock block, to possible rock falls from old workings.
The present invention eliminates these disadvantages by offering a skid device whose hydraulic components are protected at all times and wherein the length is significantly reduced, particularly in the direction of the old workings.